Software Engineer
I build production web applications, APIs, and backend systems using Python, Django, PostgreSQL, and modern cloud infrastructure — with experience across payments, SaaS, AI, and blockchain.
01 // Profile
About Me
I'm Olanrewaju Alaba — Chryzcode, a backend-focused full-stack software engineer with 5+ years of experience building web applications, APIs, SaaS platforms, and production systems.
My core backend stack is Python, Django, Django REST Framework, PostgreSQL, and API development, with experience deploying and maintaining applications across cloud platforms.
I also work with React, Next.js, TypeScript, Node.js, MongoDB, Stripe, and modern frontend tooling, allowing me to build products end-to-end. Much of my work has involved systems around payments, subscriptions, e-commerce, authentication, AI-powered applications, blockchain, and third-party API integrations.
I'm particularly interested in backend architecture, reliable APIs, data-intensive applications, cloud infrastructure, and building software that can move from an idea into a real production environment.
02 // Capabilities
Skills & Expertise
Backend Engineering
Frontend Engineering
Cloud & Infrastructure
Payments & SaaS
AI & Blockchain
03 // Competencies
Engineering Focus
Backend Engineering
Building reliable APIs, backend services, authentication systems, business logic, and database-driven applications.
Full-Stack Applications
Building production web applications from backend architecture and APIs through responsive React and Next.js interfaces.
Payments & SaaS
Building checkout flows, subscription systems, payment integrations, webhooks, and SaaS functionality around real business requirements.
AI & Automation
Integrating AI and automation into applications, APIs, and business workflows to create practical product experiences.
Cloud & DevOps
Deploying and maintaining production applications using cloud platforms, containers, CI/CD, and modern deployment workflows.
Blockchain
Building blockchain applications and smart-contract integrations for payments, asset management, and decentralized applications.
04 // Portfolio
Selected Work
ClearPeak Trading
Problem:Professional traders lacked a unified performance analytics system with high-probability indicators.
Engineering:Built a scalable SaaS platform using Next.js, PostgreSQL, Prisma, Stripe, and Auth.js, with webhook-driven state machines for payment cycles.
Result:Enabled real-time trade logs and visual statistics while protecting proprietary calculations under strict API guards.
NexaPay
Problem:Accepting Web3 crypto payments is fragmented and lacks unified dashboard management.
Engineering:Architected an interface mapping custom EVM smart contracts (Solidity) to Next.js clients using Ethers.js.
Result:Delivered a secure system with real-time txn verification, minimizing decentralized payment friction.
AI-powered MLA Draft Tool
Problem:Academic formatting standards are tedious to structure dynamically under user parameters.
Engineering:Integrated OpenAI APIs with an automated Next.js workflow, persisting user logs in MongoDB.
Result:Generated comprehensive, correctly cited MLA papers with automatic conversion to downloadable Microsoft Word (.docx) files.
Travel Leaf API
Problem:Third-party integrations in travel platforms require high latency management, rate limiting, and robust authentication.
Engineering:Built a Node.js/Express REST API utilizing Passport.js (JWT/OAuth), MongoDB schemas, Cloudinary media storage, and security middlewares.
Result:Shipped a secure backend system with clean Swagger documentation, structured rate limiting, and secure sessions.
YCSYH
Problem:Digital beat storefronts suffer from download link leakage and unfulfilled purchases.
Engineering:Developed a clean TypeScript/Next.js store leveraging Stripe sessions and automated PDF invoice/license generators.
Result:Protected intellectual assets with expiring, pre-signed content delivery links triggered upon webhook verification.
MathPoint
Problem:Gamified mathematics learning tools require responsive client interfaces alongside secure database synchronization.
Engineering:Developed user dashboard and progress systems in Next.js, syncing metrics into MongoDB.
Result:Created a high-performing pedagogical portal supporting customized worksheets and lesson logs.
FWC26 Website
Problem:Organizing multi-channel lead pipelines for high-traffic events requires extensive manual triage.
Engineering:Consolidated Stripe checkout hooks, Mailchimp lists, Calendly event triggers, and OpenAI chatbots under a Next.js hub.
Result:Automated prospect inquiries and booking workflows for FIFA World Cup 2026 local consultants.
05 // Employment
Work Experience
Lead Engineer
- Led backend architecture and feature delivery for a scalable global marketplace, integrating logistics, payments, negotiation workflows, and enterprise operations.
- Built real-time DHL shipping integration and manual tracking for non-integrated carriers.
- Architected a 'Preferred Designer' negotiation system with dynamic bid recalculations and enhanced recommendation algorithms.
- Overhauled payout systems, integrating Stripe, PayPal, BNPL, and custom wallets with real-time reconciliation.
- Developed enterprise-tier user flows, tiered permissions, and admin dashboards for order and fulfillment management.
- Implemented secure onboarding with identity verification, real-time messaging, and AWS S3 media management.
Backend Engineer
- Led backend development, building robust APIs, securing infrastructure, and designing core database layers.
- Integrated payment gateways (Paystack, PayPal) and USSD systems via Africa's Talking platforms for accessible transactions.
- Shipped features like 'Scoreboard' for the core EdTech application, improving student interaction and platform metrics.
Backend Engineer (Contract)
- Built background automated systems enabling users to extract LinkedIn data, manage lead targets, and schedule email campaigns.
- Integrated secure subscription checkouts via Stripe, mapping role-based access permissions dynamically across the database.
- Hosted infrastructure components on AWS, tuning configurations for scalability and load protection.
06 // Methodology
How I Work
Understand
I clarify the business requirements, performance constraints, user profiles, and technical requirements before writing any code.
Design
I define the system architecture, database models, API specs, security middleware, and integration strategies.
Build
I develop modular code, implement robust test coverage, verify security protocols, and integrate third-party dependencies.
Ship
I deploy applications to reliable cloud platforms, configure monitoring tools, document APIs, and iterate based on telemetry.
07 // Endorsements
What People Say
"It was a pleasure working with Olanrewaju. He demonstrated strong communication skills and a great ability to follow direction. Most importantly, we collaborated effectively to achieve our vision."
"I couldn't be happier with the work. Communication was clear, professional, and consistent. They went above and beyond to solve unexpected challenges, explained solutions clearly, and made sure everything worked exactly as promised. Highly recommended."
"Was able to solve my coding problem with my smart contract. Very knowledgeable, would recommend him and will continue to use him for future projects. Thank you."
08 // Communication
Let's Build
I'm open to backend and full-stack engineering opportunities, interesting product collaborations, and selected contract work.